title: A LC/QTOF-MS/MS application to investigate chemical compositions in a fraction with protein tyrosine phosphatase 1B inhibitory activity from Rosa rugosa flowers.
abstract: BACKGROUND
  Rosa rugosa flowers used as herbal medicine possess many activities. A fraction extracted by ethyl acetate exhibited strong inhibitive activity against protein tyrosine phosphatase 1B (PTP1B) in vitro.
  
  
  OBJECTIVE
  Establish an efficient method of LC coupled to quadrupole time-of-flight (QTOF) with tandem MS/MS to investigate the compositions in the active fraction.
  
  
  METHODS
  Chemical compositions were separated and investigated by LC/QTOF-MS/MS in negative electrospray ionisation (ESI) mode at different collision energy (CE) values. The maximal structural information was obtained for the identification of components.
  
  
  RESULTS
  A total of 75 compounds including tannins, their related compounds and flavonoids were identified or partially characterised according to accurate mass and the characteristic fragments at low and high CE. Meanwhile, the fragmentation pathways of gallotannins and ellagitannins (hexahydroxydiphenoyl group and lactonised valoneoyl group) were studied and proposed and were used to trace tannins in crude extracts.
  
  
  CONCLUSIONS
  The results suggest that this fraction is a source of PTP1B inhibitory activity with a potential for treating diabetes.
authors.affiliation: Key Laboratory of Xinjiang Indigenous Medicinal Plants Resource Utilization, Xinjiang Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Urumqi, 830011, China.
authors.forename: Dongyu
authors.initials: D
authors.lastname: Gu
authors.forename: Yi
authors.initials: Y
authors.lastname: Yang
authors.forename: Mahinur
authors.initials: M
authors.lastname: Bakri
authors.forename: Qibin
authors.initials: Q
authors.lastname: Chen
authors.forename: Xuelei
authors.initials: X
authors.lastname: Xin
authors.forename: Haji Akber
authors.initials: HA
authors.lastname: Aisa
mesh_terms: D002853:Chromatography, Liquid; D004791:Enzyme Inhibitors / Q000302:isolation & purification* / Q000378:metabolism; D005419:Flavonoids / Q000302:isolation & purification* / Q000378:metabolism; D035264:Flowers / Q000737:chemistry; D010936:Plant Extracts / Q000737:chemistry*; D054562:Protein Tyrosine Phosphatase, Non-Receptor Type 1 / Q000037:antagonists & inhibitors / Q000378:metabolism*; D027826:Rosa / Q000737:chemistry*; D053719:Tandem Mass Spectrometry; D013634:Tannins / Q000302:isolation & purification* / Q000378:metabolism
chemical_list: D004791:Enzyme Inhibitors; D005419:Flavonoids; D010936:Plant Extracts; D013634:Tannins; C516607:PTPN1 protein, human; D054562:Protein Tyrosine Phosphatase, Non-Receptor Type 1
keywords: LC/QTOF-MS/MS; Rosa rugosa Thunb flowers; flavonoids; protein tyrosine phosphatase 1B inhibition; tannins